Managing ConfigMaps

kubectl create cm app-config \
  --from-literal=LOG_LEVEL=info \
  --from-literal=API_URL=https://api.example.com

kubectl create cm nginx-conf --from-file=nginx.conf
kubectl create cm app-config --from-file=key=path/to/file
kubectl create cm certs --from-file=./certs/      # all files in dir

kubectl create cm app-env --from-env-file=.env

apiVersion: v1
kind: ConfigMap
metadata: { name: app-config }
data:
  LOG_LEVEL: info
  app.properties: |
    server.port=8080
    spring.profiles.active=prod
binaryData:
  truststore.jks: BASE64...

kubectl get cm
kubectl get cm -A -o wide

kubectl describe cm app-config
kubectl get cm app-config -o yaml

env:
- name: LOG_LEVEL
  valueFrom: { configMapKeyRef: { name: app-config, key: LOG_LEVEL } }
envFrom:
- configMapRef: { name: app-config }
- configMapRef: { name: feature-flags, optional: true }
  prefix: FF_

volumes:
- name: cfg
  configMap:
    name: nginx-conf
    defaultMode: 0644
    items:
    - { key: nginx.conf, path: nginx.conf }
containers:
- volumeMounts:
  - { name: cfg, mountPath: /etc/nginx/nginx.conf, subPath: nginx.conf }

configMap:
  name: certs
  items:
  - { key: tls.crt, path: server.crt, mode: 0400 }

apiVersion: v1
kind: ConfigMap
metadata: { name: app-config }
immutable: true
data: { LOG_LEVEL: info }

kubectl delete cm app-config
kubectl delete cm -l app=web